Product Type: Optical Experiment Product use: Convex/concave lens imaging method/determination of focal length Structure: removable Product weight: 1.8KG Product size: 12*96cm Include: 1*Optical Optical bench Note: If you have any questions about the product, you can write to us and we will reply to your questions as soon as possible★Tips: *Due to manual measurement there may be some errors please allow 1-3cm difference thank you. *Because the spotlight and different people have different understandings of color there may be a certain color but within a reasonable range please choose carefully. *If you need other styles please contact me our store has a variety of styles and colors you can view my store. *We believe that we can meet your needs with high quality products. If you find any problems with our products please feel free to contact us by email to resolve the issue. *Welcome your sharing and feedback so that we can provide you with better products and services.